[mythtv-users] Slightly OT - Help w/Homebrew IR Transceiver

[Dan Morphis]

Brian Rumple wrote:

>  I'll start with the last one first, I only believe that excess
>  voltage would damage these parts but not polarity. The basis for
>  this is very little knowledge and some experimenting when building
>  mine. I swapped things around many times trying to debug my circuit.
>  I've forgotten 98% of what I learnt in that one college hardware
>  course.
Unless your dealing with an electroletic cap.  You can cook them with 
the wrong polarity.

>
>  It sounds like you have a good handle on building this thing. I
>  didn't notice anything wrong while skimming your message. I would
>  suggest building and testing on a breadboard before solder
>  everything.
There are two types of breadboards.  Solder and solderless ones.

>
>  Last week I tried building a receiver with the 276-640. I think that
>  it should work, but all my values from irrecord are the compliment of
>  what the real number should be (e.g. FFFF is coming out 0000). There
>  is a sense option to lirc_serial module, but if a change it I get no
>  response from mode2. Do you mind sending me your experience after you
>  build yours?
>
>  The transmitter is real simple and works great. Not very much range
>  though.

Really?  I used the 276-0137B and the range is awesome.  I wonder what 
package the -640.  I know the -0137 is a repackaged sharp.  I bring that 
up because I got some of the panasonic's listed on the lirc.org site and 
their range blew chunks.  literally, unless I was within about an 8 
degree range of the receiver, it wouldn't send the signal.  I traced it 
with a friends scope and it turns out that outside of that 8 degree 
range, the signal wasn't being amplified enough by the onboard amp on 
the panasonic receiver transistor/diode combo.  You could get around 
that by bumping up what the transister in the lirc.org circuit sent.  
But that was to much trouble for me to figure out.

-dan